Selecting mechanism.



A. E. CASE.

SELECTING MECHANISM.

APPLICATION FILED DE(J.19, 1910.

Patented May 19, 1914.

3 SHEETS-SHEET 1.

7239mm R' g g A. E. CASE.

SELECTING-MECHANISM.

APPLIOATION mum mac. 19, 1010.

Patented May 19, 1914.

'a sums-BERT 2.

A. E. CASE.

SELECTING MECHANISM.

APPLICATION FILED D20. 19, 1010.

Patented May 19, 191i 3 SHEETS-SHEET 3.

NITED STATES PATENT orFIcE.

ARTHUR E. CASE, OF CHICAGO, ILLINOIS, ASSIGNOR TO DELTA ELECTRIC COMPANY, OF MARION, INDIANA. A CORPORATION OF INDIANA.

snmaccrmc MECHANISM.

Specification of Letters Patent.

Patented May 19, 1914.

Application filed December 19, 1910. Serial No. 598,265.

To all whom it may conccm Be it known that I, Airmen E. Case, a

resident of Chicago. in the county of Cook Mechanism, of which the following is a full,

clear, and exact description. I

The invention relates to apparatus adapted to be used in connection with multiparty telcphonelines, for selectively connecting substations to the line for speech-transmission and the invention designs to provide improved apparatus for sending; impulses over a multi-party line, to telcphonically connect a selected station to the line. to lock out the remaining sub-stations from the line, and to signal or ring; the selected sub station.

The invention also designs to provide improved apparatiis for this purpose whcrel v the exchange-operator can quickly cause the selecting, locking-in, locking-(mt.- aud naling" operations for multi-station lines, to be effected. f

The invention consists in the several novel features hereinafter set forth and more particularly defined by claim at the conclusion hereof.

In the drawings: Figure l is a diagrammatic view of a lock-out telephone system embodying the invention. Fig. is a diagrammatic view of the sub-station apparatus connections adapted to be operated by the selective calling stepping-up apparatus at the exchange, Fin. 3 is an elevation of the selector-switch and associated parts. l 'ig. lis a section taken on line 4 of Fig. 3. Fig. 5 is a side elevation of the master-key.

Fin. 6 is a section on line (3---(5 of Fig. 5. j

Fig. 7 is a section taken on line T-i" of Fig.

The improved selecting and calling appa ratus is adapted for use in connection with the operation of multi-partv lines. in which each sub-station is usually equipped with an electro-nuurnetically operated steppingaip mechanism which serves to lock in one or two selected sub-stations on the line and to lock out all the rest, the device under the control of the 0X(tl12l1l 2'0OPGIMQOI' operating the stepping-up mechanism automatically to lock in the selected station, to lock out all the rest and to signal the sub-station. a

A sub station equipment for which the selective mechanism is adopted, is diagrammatically illustrated in Fig. 2 and comprises a polarized stepping-up electro-magnet a, an arm (1, adapted to be operated in either dircction from its centralized normal-position by impulses of opposite polarity and a pawl a carried by said arm for stepping up a ratchet o when impulses of positive polarity are sent through magnet a. The ratchet a? carries a wiper-contact a? which is adapt cd to engage a swilch-contact a. of a circuit which controls a locking-in magnet a and said ratchet has a cam which is adapted to operate a group of switch contacts 90, 91

and 92 which control a ringing circuit at the substation. The locking-in magnet a controls a group of switches 98, J9, a (1.", u" which control a circuit for speech-transmission. The wiper-contacts (1' a't the sub-stations respectively, are timed to successively engage contacts o" respectively so that by selectively sending an impulse of alternating current over a circuit in which said contacts are included. any sub-station on the multiparty line may be locked in or telephonically connected to the line. An im pulse of negative polarity causes magnet c to operate arm a. in the opposite direction. to release a detent which holds ratchet a? and permits the ratchet to be restored to its normal position, by a retraction spring as well undcrstoml in the art. It will be on dcrslood that any desired number of sol stations may be connected to a party-line. each station being provided with similar mechanism for controlling the substation connections with the line.

llach party-line comprises conductors l. 7/ extending between the exchange and tho sub-stations. These conductors terminate in a spring-jack I) ct'the exchange and a suitable line-signal r: is connected to the springjack, as well understood in the art.

The exchange is provided with a cordloop. to which an answering-plug d, a call i,n .;plu c' (1. a listcningdvcy f, a ringing ltcy f for the calliugdinc, and a ringing:- lcey for the called line, of usual construction and arrangement, are connected in usual manner, as will be clear from Fig. l of the drawings.

A continuously operating make and-brealt device G comprises an arm which is caused to vibrate continuously by a magnet g which is included in a local circuit 9, and is con trolled by a contact g on army and a stationary contact 9 WJhen vibraJor-arm g is in position to close the local circuit 9 magnet 9* will be energized to shift the vibrator-arm and break the local circuit, and this will cause the arm to be continuously vibrated. Thiscontinuously vibrating arm controls circuits for alternately transmitting impulses of opposite polarity over the telephone-line, by vibrating between a contact 9 in a circuit for high potential of one-polarity for sending stepping-up impulses over the line, and Contact g in a circuit for low po- -mg-keys ofthe cord-loop and controls a group of switch-contacts Z, Z Z F, Z 2". Contacts Z Z? are normally in engagement and are included in a circuit over which an initial impulse is sent by the vibrator G and are separated when the magnet L is energized to interrupt this circuit, and contact Z is shifted into engagement with contact Z so that current for causing electro-magnet L to remain energized will be directed to flow through a resistance-coil Z7. The winding of magnet L- is connected by a conductor 15 to a conductor 15 which is connec ted'to the positive side of battery Said winding is also connected by a conductor 16 to contact Z. A conductor 17 is connected to contact Z resistance-coil Z and a contactl8 of a key is. Contact Z is connected to the negative side of battery 2', by conductor 61 and is normally in engagement with contact 1. The latter is connected bya conductor 65 to the winding of an electro-magnct 67 for stepping up a selector-switch M, and when contact 2' is shifted by energization of magnet L, it will engage contact Z? which is connected by a conductor 55, to the vibratorarm 9'', to close a circuit for causing impulses to pass through the magnet of the selectorswitch M. Magnet is, for convenience,-

usually mounted on the frame m which supports the-selector-switch.

Selector-switch M; is provided. for causing an impulse of. alternating current to pass over conductor Z) of the line to the stepping up relays at' 'the sub-stations, to cause the selected station to be .telephonically connected to the telephone-line. This selectorswitch is operated' by a polarized electro magnet; haying windings 67 and an arm m, which is normally held in its central position hyspring-pressed levers m? which are pivoted to a suitable frame m, as at m and engage a stud m on said arm. This arm m is operated in one direction from its cen-' tralized osition,' by current of one polarity (positiveg passing through windings 67, to shift a pawl m which steps up a ratchetwheel m. A detent m holds the ratchet wheel between the stepping-up movements of pawl m Arm mis shifted in the opposite direction from its normal central position by current of opposite polarity (negative) passing through windings 67, to cause a stud m to strike the tail of dctcnt m and disengage it from the ratchet to cause the tail of pawl m to be arrested by an abutment-on the frame as shown in Fig. 3, to also disengage said pawl from the ratchet. When said detent and pawl have been thus released, the

ratchet will be restored to its normal position, by a spring m An arm m is secured to rotate with ratchet 9228 and carries a brush-contact m adapted to successively engage a series of segment-contacts r. These segment-corn tacts are electrically connected to contacts 71 of a corresponding series of keys 7c respectively, which are operated to determine which station on a line shall be connected to the line for speech-transmission and signaling. There is one of such segment-contacts r and one key is for each sub-station on the line. Each contact 71 is connected to one of the segment-contacts 1" by a conductor 74, and all of the contacts 72 of the series are connected by a common conductor 7 3 to vibrator-contact g, which is included in a circuit over which an impulse of alternating current will pass when-brush-contact m engages one of the segment-contacts r and the contacts 71,72 of the corresponding-key 7c, are closed. These keys is are adapted to be held in depressed position by a common spring-pressed locking-member Ye and any key, which is held in depressed position thereby, will remain in depressed position to hold its switch closed until another key is depressed. Depression of any key will initially operate the locking-member to release a depressed key, and said member will, after releasing a depressed key, hold the key lastdepressed, by means of teeth 70. All of the keys 7c are mounted in a suitable frame 71: and a series of keys is, 70 k and 70 are also mounted in this frame and are adapted to be released when any of these keys or any of the keys of the series 70 are depressed.

Ratchet-wheel m carries an abutment m which is adapted to engage a switch-contact 76 to cause the latter to engage a contact 75, to establish a circuit which causes the opercally establish a signaling or ringing circuit, whereby theselected sub-station on a multi-party line will be signaled after it has beentelephonically connected to the line. H

ation of a ringingmagnet O, to automati-.

Electro-inagnet O automatically controls a ringing-circuit for signaling the selected sub-station on'the line, and comprises a winding 79 which is included in a" circuit whichis initially established by contacts 75,

76 and in a conductor 70 which is connected switches- 0 0, 0", 0 0*, 0 0. 0. Contacts are normally engaged and are connected to the circuit for sending iinpulses over the line and are opened when "the ringing magnet is energized after the stepping-up and' selecting impulses have been, sent over the line. Contact 0 is connected to a contact 53 of a key 70, by anon.-

ductor 54 and contact 0 is connected .to vi- 'brator-arm g, by a conductor Contacts 0, 0'? are normally engaged and contact 0 is connected to a wire 61 which leads to the negative side of battery i, and contact 0 to a conductor which is connected to the winding 67 of themagnet of the selectorswitch and to contact Z Contacts 0,, 0, are included in the circuit for causing magnet L toremain operative to retain the circuits for transmitting impulses, complete. When magnet O is energized, contact 0 is separated from contact 0 to cause'magnet L to become denergized so that the switchgroup controlled by magnet'L, will be re stored to normal position'to render the impulse sending device inoperative to transmit impulses over "the line. Contacts 0 0, are normally open and when magnet O is energized, contact 0 will cause said contacts to engage each other and be in contact therewith.

Contacts 0 0 0, when closed, will establish a circuit for automatically sending a releasing impulse of opposite polarity to that used foiustepping up the selector-switch through windings ,67. Contact 0 is connected by conductors 15",15", 15 to the positire side of the battery 1', and contact 0 is connected by conductor 60, to the winding 67.

Contact 0 is connected by conductor 17 to the tip side of the line, and closes a circuit for current through holding-magnet H, when magnet O is energized. Said circuit will be as follows: battery 2', conductors 15, 15, .15 contacts 0 0, conductor 17, contacts 18, 19, conductor 20, contacts 21,,22,

' '-"cond uctor 23 ,eontacts, 25, cond c contacts 27, 28, conductors 29, 30, 31, contacts32, 33, conductor 34, the tip of plug (1, the tip spring of jack b line-conductor I), through all of the stepping-41p coils on that line. conductor I), the sleeve-spring. of jack 52, 53, conductor54, contacts 0, 0, conduc- 5 tor the coil of magnet H, conductors 80 to the negative side of battery 7 Contact '0 is connected to a conductor 80 in which the winding of a holding-magnet H is included, and when magnet O is cner- 3e 'gizcd, contact 0 will move into engagement with contact 0 to cause a circuit to be established through magnet ll. Conducton 8O 1s connected to conductor 80, which is con nected to the negative side of the battery 2',

and when contact is broken at 75, 76 by release of the selector-switch, ringing mag net 0 will remain energized. Contacts h, Ii, which are operated by the holding-relay II, will be closed to complete a circuit for causing magnet O to remain operative. to complete a ringing-circuit between contacts 0 0 and 0' which are connected to the ri n gin g-circui t.

Kc is com arises contacts 52 53, 18 1.)

.l l 9 i and connections for controlling a circuit whereby stepping-up impulses may be manually sent over the telephone'line by the exchange-operator. Key 71 comprises ,con-

tacts 49, 50," 21 and QQ-and connections whereby alternating current may be inanm ally sent over the line by the exchange-operator. Key it" comprises contacts 113, 46,

'47, 24, 25, 1152 and connections for manually controlling a circuit whereby a releasing impulse may be sent to all the sub-stations on the calling and called lines before the disconnection is made between the exchange and said lines. Key 7r comprises contacts 43, 44, 27, 28 and connections whereby the exchange-operator can scndgenflator current over a single party line. Contact 48 of key M is connected to conductor 41 of the cord-loop, by a conductor 42, and contact 28 is connected to the other branch 30 of the" cord-loop-by a conductor :29.

The operation, in detail, of the system illustrated as an exemplificalion of the invention will he as follows: Any sub-station connected to the exchange by a inulti-party line b, b may signal the exchange-operator, by operating the magneto-generator located at such sub-station, which will cause genei ator current to pass over the metallic circuit of the line and operate the linc-signal c, as well understood in the art. In re sponse to this signal, the cxchrange-operator will insert an answering-plug (Z into the springjaclr i" oi the line over which the signal ream a, and will operate the 1istoning key j? to establish a circuit for speechtransmission between the operators tele phone set 6 and tin .allingsub-station, by means of the usual circuit connections and apparatus illustrated in the drawings and Will ascertain the number of the calling senstation and the number of the sub-station with which connection is desired. Thereupon, the exchange-operator will operate the selective-mechanism to'cause impulses to be sent over the calling line to operate the stepping-up mechanism at all of the substations and to .telephonically connect the selected station to the line, and to lock out all others. In this operation the exchangeoperator will first operate that key is corresponding in number to the calling sub-station, for example, No. 6. Next, the exchange-operator will shift the ringing-key f for the answering-plug which has been inserted into the sprmgack of the calling line. Thereupon, a circuit will be established for the operation of magnet L as soon as the vibrator-arm 7 engages contact 9 which is connected to battery '21, said circuit being as follows, viz.: battery 2', conductors 15, 15, the Winding of the magnet L, conductor 16, contacts Z, Z conductor 17,- switch-contacts 18, 19 of key is, conductor '20, contacts 21, 22 of key 76 conductor23,

contacts 24:, 25 of key conductor 26, contacts 27, 28 of key 10 conductors 29, 30 and .31, contacts 32, 33 of ringing-key f, conductor 34, the tip-contact of plug (l, the tipspring of spring-jack b line-conductor Z), all of the conductors 36 of the sub-stations an the line in which the stepping-up electromagnets a are included, line-conductor Z), the sleeve-contact of the spring-jack b the sleeve of plug (Z, conductou l', contacts 38,

59 of ringing-key f, conductors 40, 41, 42,

that their armaturcs will be operated to release the steppingup mechanisms (if any are not in normal position) and insure their. being in'normal position at the commencement of each calling or stepping-up operation. This initial impulse of 62 volts energizes electro-magnet L and causes it to shift switch-member Z out of contact with switchmember Z and into contact with a switchmember'l and also operates contact Z out of contact with member Z and into contact with a contact Z to establish circuit for causing impulses to be sent over the telephone line and through the magnet of selector-switch M. The shifting of the switch-group controlled by elect-ro-magnet L interrupts the circuit last described and causes a circuit to be established for holding this switch-group-in shifted position, said circuit being as follows: battery 71, conductors 15, 15, the winding of magnet L, conductor 16, resistance-coil l (2000 ohms), conductor 17 switch-members Z Z conduetors 59, 60, contacts 0 0" of relay 0, conductor 61 to battery 2'. Resultant-1y, the starting relay L will remain energized and will hold the group of switches controlled thereby in shifted position until the operation of theselector-switch has been completed and this current is interrupted at contact 0. 0 by the operation of the ringing-relay O. 5

It will be observed that a starting impulse is impressed upon the line only when the vibrator-arm g engages contact g which controls the flow of potential from the low voltage battery 11, and before the steppingup circuits become operative, so that an impulse of the aggregate voltage of batteries i, i (say 62 volts) is impressed upon the circuit including the stepping-up relays a. at the sub-stations when the starting-magnet L is actuated, and an important advantage of this arrangement and construction is that the-circuit, next to be described for the stepping-up operations will always be established when the vibrator is in one of its alternative posit-ions and before the first stepping-up impulse is sent over the line, and that a releasing-impulse will be initially transmitted during each operation.

lVhile the starting-magnet L remainsoperative and after the stepping-up relays a at the sub-stations have been restored to normal position by the initial impulse of 62 volts, a circuit for the transmission of stepping-up impulses through the relays a at all of the substations on the line, will be established. Each time the vibrator-arm g engages contact 9, a stepping-up impulse (positive 5O "oltsi will be sent over the following circuit, v1z.': battery 2', conductors 15, 15, contact 9, vibrator-arm g, conductor 55,

contacts 0, o, conductor 5i, contacts 53, 52

ofkey 7c, conductor 51, contacts 50, l9fiof key if, comluctor 48, contacts 47, 16 of key 2 ,1, conductor 45, contacts 44, 43 of key It, conductors 42, -11, 40, contacts 39, 38 of ringing-key f, conductor 37,-sleeve of plug d, sleeve-contact of spring-jack 6 line conductor Z), all of the conductors 36 at the substations on the line and in which the steppingmp relays a are included, lll'lrCOIldllC- for I), tip-contact of spring-jack b tipof: plug (Z, conductor 34: of the cord-loop, contacts 33, 32, conductors 31,30 and 29, contacfs 28, 27 of key 75*, conductor 26, contacts 25, 24c of key k conductor 23, contacts 22, 21'

of key if, conductor 20, contacts 19, 18 of key It, conductor 17, contacts Z Z conductors 59, 60, contacts 0* and conductor 01 to the negative side of battery 2'. These M to step'up brush-contact m in synchronism with the impulses to the steppingup mechanisms at the sub-stations, so that a lockingin impulse, under control of the selector switch will be transmitted to the selected station corresponding to the number of the key K (No. 6) which has been operated. Said circuit will be as follows: battery z', .conductors 15, contact 9, vibrator-arm g conductor 55, contacts Z, Z, conductor 65, the magnet-windings 67 of selector-switch M, conductor 60, contacts 0, 0, conductor 61, to battery These'impulses are also controlled by vibrator-arm g and therefore pass over said circuit in synchronism with the stepping-up impulses transsuccessively engage Assuming mitted through the stepping-up relays a at the substations-on the line, and cause the selector-switch and sub-station relays a to be stepped up together.

Between each of the stepping-up impulses last-described and every time vibrator-arm g" engages contact 9 an impulse of low potential (-12 volts) and opposite polarity (negative) will be sent over the lineto remove residual magnetism from the relays in the circuit and any electrostatic charge on the line, said circuit being as follows: battery i, conductor 56, contact 9 vibrator-arm (7 conductor 55, contacts 0 0, thence over the line and same connections traversed by the stepping-up impulses, to conductor 17, contacts Z Z conductors 59, 60, contacts 0", 0 and conductor 61 to battery i.

During the stepping-up operation of the selector-switch M, brush-contact m will segment-contacts 1' which are respectively connected to keyswitches K, to control transmission of a locking-in impulse of alternating current over conductor-b of the line to'the selected sub-station (No. 6 corresponding to the key' exchange opciilto'r to close its contacts 71,472.

No. 6" key, series K, to havev been depressed, as is done when sub-station No. (5 is to be selected and signaled, an impulse of alternating current for causing that sub-station to lie-locked in, will be, when bruslrcontact m engages the segment COD- nccted to said-key 7.1, sent over the following circuit, viz; ground it, generator at, conductor (3%), arm m, brush-contact m, that seg? ment r which is co'nnected to the key k which has been operated, its conductor 7+1,

contacts 71, 72 of the depressed key It, conductor 73, vibrator-contact 9, arm 9, condin-tor 55, contacts 3?, 0, conductor 54,

contacts 53, 52 of key conductor 51, contacts 00, -19 of key-switch k conductor 48,

contacts 47, 46 of key is", conductor 45, contacts 4A, 43 of key it, conductors t2, 41, 40, contacts 39, 38 of ringing-key f, conductor 37 of the cord-loop, the sleeve of plug d, sleeve-contact of spring-jack IF, lin'e conductor Z), conductor 3(iat that sub-station (No. at which the brush-contact a is then engaging its contacts a, conductor a, locking-in magnet a, conductor 100, to ground .101. This actuation of the magnet a at the selected sub-station operates a group of switches which connects that substation to the line-conductors for speech transmission.

It will be understood that the contacts a at the dilfcrent sub-stations on the line are disposed to be successively engaged by their lnush-coi'itacts (1 so that only the selected station will be connected to the party-line 2'), I) by the lockingin impulse of alternating curtent determined by the exchangeoperatorwlien operating one of the keys 7c. The locking-in impulse is impressed upon the circuit while the vibrator-arn'i g is out of contact with switch-member g and the locking-out impulses volts) are transmitted, while the vibrator g engages the contact from which 12 volt current is impressed upon the line, and resultantly all possibility of confusion of the stepping-up and locking-in impulses is'ovcrcomc.

W'hen impulses in sufficient number have been sent over the line to step up the relays (1, at the sub-stations and the selected station has been tclephonically connected to the line and at the end of the sweep of brush-contact m of the selector-switch M,

a circuit will be established by abutment m contact 75, whereupon the following circuit will be momentarily established, viz.: bat- -Thereupon, a circuit will be established through holding-magnet H which causes the current for magnet O to continue until the exchange-operator restores the ringing-key f to normal position, which will be as follows: battery 2', conductor (40 volts) conductors 15, 15 15", contacts 0, 0 conductors 82, 17, contacts 18, 19 of key 70, conductor 20, contacts 21, 22 of key 70 conductor 23, contacts-24, 25 of key 'lc ,-conductor 26, contacts 27, 2801 key la conductors 29, 30, 31,contacts 32, 33 of ringing-key f, conductor 34, tip of plug (Z, tip-contact of spring-jack b line-conductor Z), conductors 36 of all of the sub-stations, in which the stepping-up relays a are included, line-conductor b, the sleeve-contact of spring-jack b sleeve of plug d, conductor 37 of the cordloop, contacts 88, 39 of the-ringing-key f, conductors 40, 1-1, 42, contacts 43, 44 of key 70*, conductor 45, contacts 46, 47 of key k", conductor 48, contacts 49, '50 of key 1?, conductor 51, contacts 52, 58 of key 70', conductor 54;,contacts 0, 0", a conductor (including the winding of holding-magnet H), conductor 80 to battery i. Current passing over this circuit is of insufficient voltage to actuate the magnets a at the sub-station, being less (40 volts) than the voltage necessary (50 volts) to operate said magnets, and furthermore the winding of the holdingrelay H is of high resistance (say 3000 ohms) so that the operation of the sub-station magnets will be effectively prevented. The last mentioned circuit will complete and maintain the following ringing or signaling circuit, viz. ground't, generator 7, conductor 69, contacts 0 0", 0, conductor 54, contacts 53, 5201? key 7:, conductor 51, contacts 50, 49 of key k conductor -15, contacts 47, 46 of key 7c, conductor 45, contacts 4-4, 43, conductors 42, 41, 40, contacts 39, 38 of ringing-key f, conductor 37 offthe cord-loop, sleeve of plug (1, sleevecontact of springjack b line-conductor b, conductor 36, conduct-or 89, contacts (2 ,6 of the locking-in relay a of the selected substation, conductor 89*, contacts 90, 91 which are then held in contact by the arm of the steppingup mechanism, conductor 93, witclrhook contacts 94, 95, conductor 96 in which a bell 97 is included, contacts 98, 99 ot the lockingin magnet a, and conductor 100 to ground. 101. In this manner, the ringer for signaling the selected station will be operated to indicate to that station that-the locking-out and locking-in operations have been. completed, or when the calling mechanism is operated over a called line, the selected sub.- station willbe notified that communication therewith is desired and that a connection has been made therewith.

When the ringing-magnet O is operated as last described to automatically establish the signaling-circuit for the selected sub-station,

signaldamp g is operated at the exchange to indicate to the exchange operator, that the bell atthe substation is ringing When the ringing-magnet O is energized as hereinbefore described, the circuit through the starting magnet L will be interrupted at con-' tacts 0- 0* which will cause. the group of switches operated "by the magnet L to be restored to their normal position and this restoration interrupts the. circuit for the sclector-switch M at contacts Z Z so that no further impulses will pass through the winding 67, Thereupon, a releasing or restoring impulse of opposite polarity to that used for selectorswitch M, will be sent through the winding (37 of relay m to cause its arm. 4% to release the operating and-holding pawls of the ratchet m by which the brush-arm m is stepped up and held. The circuit for causing this releasing impulse to pass through helix 67 will be as follows, viz.: battery 2', conductor 15., .15", contacts 0, 0- 0 conductor 60, helix 67, conductor 65,

lcontacts Z Z conductor 61 tobatterve'.

The selector-switch will then'be restored to its normal position, in readiness for another operation. Next, the operator will restore ringing-key f to normal position and the will break the circuits in which the ring- 1ng-magnet O is included, which will interinterruption of the circuit at the ringing-key rupt the circuit for the holding-magnet H r at contacts k 71- whereupon said magnet i) will be restored to normal position and the signal-lamp will be extinguished. The entire selecting and calling mechanism will then be in normal position with the exception of the key K (.No. 6) which will be restored when the exchangeroperator depresses key k to send a releasing impulse over the line after the telephonic communication between the sub-stations hasbeen completed, or when any of the keys K, 7r, W, k are next operated.

While the locking-in and locking-out operations are caused by the operation of the calling and selecting apparatus, at the exchange has been described in connection with a calling sub-station, it will be understood that the same operation results when this apparatus is operated in connection with a called station when the companion-plug (Z of the cord-loop is in the springjack oi the called line and the ringing-key f is operated in lieu of the ringing-key f of the same cord-loop. As soon as the exchangeoperator has selected and signaled the called line by operation of the selecting and calling devices in like manner to that employed for locking in the calling: sub-station, all of the sub-stations on the line over Which the call is received, and on the line to whichl the called station is connected, will be locket out of the lines, except the calling sub-station and the called station, and. circuit for specch-transmission will be completed as soon as the receiver is removed from, the switchdlook at the called station, in manner well understood in the art.

\Vhen the conversation between the connected sub-stations has been completed and the usual disconnectingsignal has. heenreceived by the exchange-operater, the latter will depress key k to cause a releasing impulse to be sent to restore the stepping-up mechanisms'on all of the stations of the called line and the calling lines, to normal position. For this purpose, the exchangeoperator, in addition to operating key in will operate the ringing keys F, f, whereupon an impulse for restoring the polarized relays at all of the sul'i-stations will be established over the following circuit. viz.: battery 2', conductor 15, conductor 111, contacts 112, 25, conductor 26, contacts 927', 28 of key in conductors 29. 30. 31 contacts 32, 33 7 I 7 3 conductor 34:, the tip contact of the springjack b line-conductor 7), conductors 36 of all of the sub-stations on the line and in which the stepping-uprelays ('1 are included, line-conductor Z), sleeve-contact of the spring-jack Z1 sleeve of plug (Z, conductor 37 of the cord-loop, contacts 39, conductors +10, 41, 4-2, contacts %3, 14 of key. is, conductors 15, contacts 46, 113 of key is, conductors 114., 61 to battery 2'. This impulse will be of such polarity as'to operate the polarized magnets of the stepping-up relays a at the sub-station so as to cause the holding-pawls to release the ratchets and cause them to release the latches for the contacts operated by the locking-in relay of the connected sub-station and to restore the stepping-up mechanisms to their normal p0 sition. A like circuit through the ringing key f causes the stepping-up relays of all o't'the substations. on the called line to be restored to their normal position. Thereupon, the entire equipment will be in its normal position in readiness for another operation. If two sub-stations on the same line are to be connected for speech-transmission, the operator will, operate the corresponding keys K which willca use a locking-inimpulse.

to besent to each of said stations by the selectorswitch.

In event the vibrator should become inoperative the exchangcoperator can, when the ringingkey of. the cord-loop has been shrt'ted. sendsteppisig-up innmlsesover the lines, by 'depressing key and operating the ringing-key once for each stepping-up impulse. Contact 116 is connected to battery-conductor15, to conduct current over the impulse circuit when the ringing-key 1S operated. By means of key is", the exchange-operator may send alternating current to the selected station to lock 1t m, and

said key is provided with a contact 117 which is connected to generator-wire on.

By means of key 70, the operator can send 1 generator current over a single party line, being provided with a contact 118 which is connected to generator-wire 69.

The invention is not to be understood as restricted to the particular construction and organization set forth andmay be modified within the scope of the appended claims withoutdeparting from the spirit and scope of the invention, and while the invention hasbeen particularly described in connec tion with a multi-party telcphonesystem, it

will be understood that certain features might be embodied in apparatus for select ing and signaling over other lines, to which a number of stations are connected and which are to be selected and signaled.

Having thus described the invention',wliat I claim as new and desire to secure by Letters Patent, is: a i

1. In a lock-out telephone system, the combination with switching devices at, the substations and a line of a circuit and means for alternately sending different impulse over the line, and electro-magnetieally oper atcd means for controlling the circuit to render it operative for the transmission of impulses.

2. In a lock-out telephone system, the combination with switching devices at the substations and a line of a circuitand means for sending impulses over the line, electromagnetically operated means for controlling the circuit to render it operative for the transmission of impulses, and means for selectively transmitting a different impulse over the line between the first mentioned impulses. t

3. In a lock-out telephone system, the

combination with switching devices atthe -controlling means after the impulses have been transmitted. I

5. In a lock-out telephone system, the

' combination with switching devicesat the .thecircuit to render it perative for the sub-stations and a line of a circuit and means for sendlng impulses over the llne, electromagnetica'lly operated means for controlling transmission of impulses, 'means for selectively transmitting a different impulse oven the line between the first mentioned impulses, and means for automatically restoring the controlling-means after the impulses have been transmitted.

6. In a lock-out telephone system, the combination with switching devices at the substations and a line of a circuit and means for alternately sending different impulses over the line, electro-magnetically operated means for controlling the circuit to render it' operative for the transmission of im-,

pulses, means for selectively transmitting a different impulseover the line, and means for automatica ly restoring the controllingmeans after the impulses have been transmitted.

7. In a lock-out telephone system, the combination with switching devices atthe sub-stations and a line of a circuit and means for alternately sending different impulses over the line, a switch for controlling the circuit to render it operative for the transmission of impulses, and an electromagnet for operating the switch.

'8. In a lock-out telephone system, the combination withswitching devices at the sub-stations and a line of 'a circuit and means for sending impulses over the line, a.

' sub-stations'and-a line of a circuit and means for alternately sending different impulses over the line, a switch for controllingthe circuit to render it operative for the transmission of impulses, an electro-magnet for operating the switch, and means for selectively transmitting a different impulse over the'line.

10. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means for sending impulses over the line, a switch forcontrolling said circuit, an electro-magnet for operating the switch to render the circuit operative for the transmis sion of impulses, and means for causing the switch to be automatically restored to render the circuit inoperative after the impulses have been transmitted.

11. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means "for alternately sending different impulses over the line, a switch for controlling the circuit to render it operative for the transmission of impulses, an electro-magnet for operating the switch, and means for causing the switch to be automatically restored. to render the circuit inoperative after the impulses have been transmitted.

12. In a lookout telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means for sending impulses over the line, a switch for controlling the circuit to render it operative for the transmission of impulses, an elect-ro-magnet for operating the switch, means for selectively transmitting a difierent impulse over the line between the first-mentioned impulses, and means for automatically causing the switch to be re stored to render the circuit inoperative after the impulses have been transmitted.

13. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means for alternately, sending different impulses over the line, a switch for controlling the circuit to render it operative for the transmission of impulses, an electro-magnet for operating the switch, means for selectively transmitting a different impulse over the line, and means for causing the switch to be automatically restored to render the circuit inoperative after the impulses have been transmitted.

14- In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of. a circuit and means for alternately sending difierent impulses over the line, electro-magnetically operated means for controlling the circuit to render it operative for the transmission of impulses, and a key for controlling the operation of said electro-magnetically operated controlling-means.

impulses, and a key for controlling the op- .erated means for controlling the circuit to means for alternately transmitting difi'erent impulses over the line, electro-magnetically operated means for controlling the circuit to .render it operative for the transmission of impulses, a key foricontrolhng the OPGI'tItlOD of said electro-magnetically operated controllinganeans, and means for automatically restoring the electro-magnetically operated controlling-means after the impulses have been transmitted.

18. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means for transmitting impulses over the line, electro-magnetically operated means for controllin the circuit to render it 0perative for tlQiIEIIlSlIllSSlOIl of impulses, means for selectively transmitting a different impulse over the line between ,the first mentioned impulses, means torautomatically restoring the electro-magnetically operatedcontrolling-means after the impulses have been transmitted, and a key for controlling theoperation of said electro-magnetically operated controlling=means.

19. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means for alternately sending different impulses over the line, electro-magnetically operated means for CODtI'Olling the circuit to render it operative for the transmission of impulses, means for selectively transmitting a. different impulse over the line, means for automatically restoring the controllingmeans after the impulses have been trans mitted, and a key for controlling the opera tion of said electro-magnetically operated controlling-means.

90.111 a lookout telephone system, the combination with switching devices at the sub-stations and a line of a circuitand means for alternately sendingditl'erent impulses over the line, a switch for controlling the circuit to render it operative for the transmission of impulses, an electro-magnet diiferent impulse over the line between the first-mentioned impulses, and a key for controlling the operation of said electromagnet.

22. In a lock-out telephonesystem, the combination with switchin devices at the sub-stations anda line 0 a circuit and means for alternately sendin difi'erent impulses over the line a switch or controlling the circuit to render it operative for the transmission of impulses, an electro-magnet for operating the switch, means for selectively transmitting 'a different impulse over the line, and a key for controlling the operation of said electro-ma et.

"23. In a lock-out telep one system, the combination with switching devices at the sub-stations and a line of a circuit and means for alternately sendin difi'erent 'impulses over the line, a switch ior controlling the circuit to render it operative for the transmission of impulses, an electro-magnet for operating the switch, means for causing the switch to be automatically restored to render the circuit operative after the im pulses have been transmitted, and a key for controlling the operation of said electromagnetically operated controlling-means. 24'. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means for sending impulses over the line, a

switch for controlling the circuit to render it operative for the transmission of impulses, an eleetro-magnet for operatingv the switch, means for selectively transmltting a ditl'erent impulse over the line between the first mentioned impulses, means for automatically causing the switch to be restored to render the circuit inoperative after the impulses have been transmitted.

25. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means for alternately sending difi'erent impulses over the line, a switch for controlling the circuit to render it operative for the transmission of impulses, anelectro-magnet for operating the switch, means for selectivelytransmitting a different impulse over the line, means for causing the switch to be autoumtically restored to render the circuit inoperative after the impulses have been transmitted.

26. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit for transmitting impulses over the line, a continuously operating make-and-break device in said circuit, and electro-magnetically operated means for controlling the circuit to render it operative for the transmission of impulses.

27. In a lock-out telephone system, the combination WltlbSWltClllDg devices at the 25 ,netically operated means for controlling the sub-stations and a line of a circuit for trans ously operating make-and-break device in said circuit for alternately causing different impulses to pass over the line, and electromagnetically operated means for controlling the circuit to render it operative for-the transmission of impulses.

28. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit for trans mitt-ing impulses over the line, a cont-inuously operating make-a nd-break device in said circuit, electro-magnetically operated means for controlling the circuit to render it operative for the transmission of impulses, and means for selectively transmitting a? different impulse over the line.

29. In a lock-out telephone system, the

' combination with switching devices at the substations and a line of a circuit for transmitting impulses over the line, acontinuously operating make-and-break device in said circuit, for alternately causing different impulses to pass over the line, electromag circuit to'render it operative for the transmission of impulses over the line.

30. In a lock-out telephone system, the

combination with switching devices at the substations and a line of a circuit for trans,

mitting impulses over the line, a continu- "ously. operating make-a-nd-break device in said circuit, electro-magnetically opera-ted means for controlling the circuit to render it operative 'for the transmission of impulses, and means for causing the controlling-means to render the circuit inoperative for the transmission of impulses.

31." In a lock-out telephone system, the

mitting impulses over the line, a continuously operating make-and break device. in

said circuit, for alternately causing difierent impulses to pass over the-line, electromagnetically operated means for controlling the circuit to-render it operative for the transmission of impulses, and means for causing thecontrolling-means to render the "circuit inoperative for the transmission of impulses. 32. Ina- 1ock-out telephone system, the combination with switching devices at the substations and slim of a circuit fortransmittin-g impulses over the line, a continuously operating -make-and-break device in said circuit, 'electro-magnetically operated means for controlling the circuit to render it operative for the transmission of impulses, means for selectively transmitting a difierent impulse over the line, and means for causing the controlling-means to render the circuit inoperative for the transmission of impulses. V a alock-outtelepheue systemfthe combination with switching devices at the substations and a line of acircuit for trans mitting impulses over the line, a continuously operating make-and-break device in said circuit, for alternately causing different impulses to pass over the line, electromagnetically operated means for controlling the circult to render it operative for the transmission of impulses, means for selectively transmitting a diflerent impulse over the line, and means for causing the controllingmeans to render the circuit inoperative for the transmission of impulses.

34. In a lock-outtelephone system, 1 the combination'with switching devices at the sub-stations and'a'line of a' circuit and a make-and-break device in said circuit, 'for alternately transmittingidiiierent impulses over the line, means for controlling said circuit to render it operative-for transmission of the impulses, and means for causing said controlling-means to be actuated only when the impulse-device isin'position to cause an impulse of onecharacter to pass over the circuit.

35. In a-lock-out telephone system, the

combination with switching devices at the sub-stations and a line of aclrcuit and a make-and-break device in said circuit, for alternately transmitting difierent impulses is in position to cause an impulse of-one'.

character to pass over the circuit;

.36. In a lock-out telephone system, the combination withswitching devices at the substations and a line of a circuit and 'a' make-and-break device in sa1d.,'c1rcu1t, for

alternately transmitting different impulses over the line, elect-ro-magneti'cally operated means for controlling said circuit, means-for.

causing said magnet to be actuated only when the impulse-device is.in position to cause an impulse of one character to pass over the circuit, and a key for controlling the operation of said electro-magneticallyoperated controlling-means.

37. In a lock-out telephone system, the

combination with switching devices at the sub-stations and a line of a circuit and a 'make-and-break device in -said circuit, for, alternately sending different impulses over the line, electro-magnetically operated means for controlling said circuit, means for cans-- ing said magnet tobe'actuated only when the impulse-device is in position to cause an impulse of one;character to pass over the circuit, and means for selectively transmit-- 'ting a different impulse over the'lines 38. In a lock-out telephone systemfthe combination with switching devices at the substations and a line of a circuit and a olsub-statio'ns and a line of a circuit and a mak'e-and-break device in said circuit, for alternately sending different impulses over the line, electro-magnetically operated means for controlling said circuit, means for causing said magnet to be actuated only when the impulse-device is in position to cause an impulse of one character to pass over the circuit, and means for automatically causing the electro-magnetically operated controlling-means to render the circuit inoperative for the transmission of impulses.

39. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and a make-and-break device in said circuit, for alternately sending different impulses over the line, electro-ma netically operated means for controlling saitf circuit, means for causing said magnet to be actuated only when the impulse-device is in position to cause all impulse of one character to pass over the circuit, a key or controlling the operation of said electro-magnetically operated controlling neans, and means for automatr cally causing the electro-magnetically operated controlling-means to render the circuit inoperative for the transmission of impulses.

40. Ina lock-out telephone system, the combination with switching devices at the make-and-break device in said circuit, for alternately sending different impulses over the line, electro-magnetically operated means for controlling said circuit, means for causing said magnet to be actuated only when the impulse-device is in position to cause an impulse of one character to pass over the circuit, means for selectively transmitting a diiferent impulse over the line, and means for automatically causing the electro-magnetically operated pontrolling means to render the circuit inoperative for the transmis sion of impulses.

41. In a lock-out telephone system, the combinationwith switching devices at the sub-stations and a line of a circuit and a make-and-break device for alternately sending different impulses over the line, a switch for controlling said circuit, an electro-mag net for operating said switch, a keyfor causing the magnet to be operated, and means for causing said magnet to be actuated only when the makeand-break device is in posilion to cause an impulse of one character to pass over the line.

42. In a lock-out telephone system, the combination withswitching devices at the sub-stations and a line of a circuit and means for alternately transmitting impulses of ditl'erent polarity over the line, and means For initially transmitting .a restoring inlpulse of greater potential over the line."

43. In a lock-out telephone system, the combination with switching devices at .the

sub-stations and a line of a circuit and means for alternately t'ansmitting impulses of different polarity and potential over the line, a switch for controlling said circuit, an electro-magnet for operating said switch, a l cy for controlling the operation of said magnet, and means for transmitting an impulse of greater potential through saidmagnet and over the line.

44. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and for-controlling transmission of locking-in.

impulses, aswitch for successively engaging said contacts to selectively cause an im pulse to be sent overthe line, an electromagnetfor operating said switch, means -for alternately sending different impulses over the line, and means for transmitting impulses of one character to said magnet to step up said switch. t

$6. In .a" lock-out telephone. system, the combination with switching devices at the sub-stations and a line of a series of contacts for controlling transmission of locking-in impulses, a switch for successively engaging said contacts to selectively cause an "impulse to be sent over the line, an electro-magnet for operating said sw1tch, means for alter natelysending different impulses over the line, means fol-alternately transmitting like impulses to said magnet, and a series of keys switches respectively connected to said contacts for selectively controlling the transmission of impulses by the elcctro-magnetically operated switch.

47. In a lock-out telephone systemi' the' combination with switching devices'at the sub-stations and a line of a selectorswiteh, an electro1nag11et for stepping up said switch, means for synclnonously causing impulses to be sent over the line and to said magnet to step up said switch, and means for selectively controlling the transmission of an impulse over the line by theselectorswitch, and nieans.for automatically establishing ,a signaling circuit after the sclector-switch has been stepped up.

4.8, In a lock-out telephone system, the combination with switching devices atthe sub-stations and a line of a series of con (acts for controlling transmission of lockingin impulses over the line, an elect'rn-magnetically operated switch for successively engaging said contacts, means for selectively controlling the transmission of impulses by the operation of said switch on said contacts, and means for automatically establishing a signaling circuit afterv the selector-switch has been stepped up.

49. In a; lock-out telephone system, the combination with switching devices at the sub-stations and a line of a series of contacts for controlling the transmission of lockingin impulses over the line, a switch for successively engaging said contacts for selectively sendingan impulse over the line, an elect-ro-magnet for operating said switch,

;means for synchronously sending impulses throughsaid magnet and over the line, and

means for. automatically establishing a signaling-circuit after the selector-switch has been stepped up.

an electro magnet for steppingup said switch, means'foi" alternately transmitting difi'ercnt impulses over the line,vmeans for sending impulses .of one character to said magnet to step up the switch, and means for automatically,establishing a signalihg' cir.

vcuit after the selector-switch has been stepped up.

51'. Inv a combination with switching devices at-Ithe substations and a line of a selector-switch,

an 'electro magnet for stepping up said switch means for alternating transmitting different impulses'overthe line, means for sending impulses of one-character to said magnet'to step-up the-switch, means for selectively controlling the vtransmission of an impulse over the line by the selector switch, an

switch has been stepped up.

52'. Inia lock-outtelephone system, thecombination with switching devices at thesubstations and a line of aselector-switch, a'nv-electro-magnet for; stepping up said switch, means for alternately transmitting difierent "impulses over the line, means for sending impulses to said magnet,-keys. for selectively controllingv the transmission of impulses by the switch, and means for auto substations and afline of aseries of contacts for-operating sa-id switch, means for altermatically establishing a signaling circuit after theselector-switch hasb'ecn stepped up. v 53. In a lock-out telephone system, the

combination with switchingdevices at the for controlling transmission of locking-in impulses, a switch for successively engaging said contacts to selectiveiy cause an impulse to be sent ever theline, an electro-magnet nately sending different impulses over the line, means for transmitting impulses of one character to said magnet to step up said switch, and means for automatically estab- 50. In a lock-out telephone system, the, combination with switching devices at the sub-stations and a line of a selector-switch,

lock-out telephone system, the

means for automatically estab-' lishing a signaling circuit after the selector- Iishing a signaling circuit after the selector switch has been stepped up.

54. In a 'lock-out telephone system, the combination with switching devices at the sub-stations and a line of a-serics of contacts 'nalingcircuit after the selector switch has been stepped up. I a

55. In a, lookout telephone system, the combination with switching devices at the sub-stations and a line of aselector-switch, an electromagnet for stepping-up said switch, means for synchronously sending impulses to said magnet to step-up the switch, and over the line, and "means for automatically sending ringing current over the line itfter the impulses have been sent over the ine.

*56. In a lock-outtelephone system, the

combination with -s'witching-dvices at the sub-stations anda line of aselector-switch,

an electro-magnet for stepping up said switch, means forfsynchronously sending impulses over the line and to said. magnet to step up said, switch, means for selectively controlling the transmission" of an impulse over the line by the selector-switch, and means for automatically sending signaling current over the line when said switch has I been step'ped'up by said impulses.

- 57. In'a'flock-out telephone system, the

combination with switching devices at the sub-stationsanda line of a slectgr-swittzh, anelectr c-magnetfor stepping up-said switch, means for alternately transmitting different impulses over theline, means for sending impulses of one characterto said magnet to step up the switch, and means for automat cally sending signaling current over the line when saidswitch has been stepped .up by said impulses.

"'58. In a lock-out telephone system, the

combination with switching devices at the sub-stations and a line of a selector-switch, .anlelec-tro-magnet for stepping up said switch, vmeans for alternately transmittingdiflerent impulses over the line, means for sending impulses ,of one character to said magnet to step up the switch, means for automatically sending signaling current over the line when said switch has, been stepped up, and means for rendering the impulsesending means inoperative when ringing current is sent pver the l ne.

combination with switching devices at the 59. In a lock-out telephone system, the

sub-stations and a line of a selector-switch,

an electro-magnet 'for isteppi-ng up said switch, means for alternately transmitting difi'erent impulses over the line, means for sending impulses of one character to said magnet to step up the switch, means for selec'tively controlling the transmission of an impulse over the line by the selector-switch,

' and means for automatically sending signaling current over the line when said switch has been stepped up.

60. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a selector-switch, an electro-magnet for stepping up said switch, means for alternately transmitting difi'erent impulses over the line, means for sending impulses of one, character to said magnet to step up the switch, means for selectively controlling the transmission of an v impulse over the line by the selector-switch,

means for automatically sending signaling current over the line when said switch has been stepped up, and means for rendering the impulse-sendingmeans inoperative when ringing current is sent over the line.

61. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a selector-switch,-

an electro-inagnet for stepping up said switch, means for synchronously sending impulses to said magnet to step-up the switch and over the line, electro-ma netically oper ated means for controlling t e operation of the impulse-sending means; and means for automatically rendering the impulse-send ing means inoperative after each steppingup operation has been completed.

62. In a lock-out telephone system, the

combination with switching devices at the sub-stations and a line of a selector-switch,

an electro-magnet for ste ping up said switch, means for alternate y transmitting difierent impulses over the line, means for sending impulses of one character to said magnet to step up the switch, and electromagnetically operated means for controlling the operation of the impulse-sending means.

63. In a lock-out telephone system, the

combination with switching devices at the sub-stations and a line of a selector-switch, an electro-magnet for stepping up said switch, means for alternately transmitting different impulses over the line, means for sending impulses of one character to said nagnet to step up the switch, electro-magnetically operated means for controlling the opera tion of the impulse-sending means, and

means [or automatically rendering the im-' pulse-sending means inoperative after each stepping-up operation has been completed. 64. In a lock-out telephone system, the

7 combination with switching devices at the sub-stations and a line of a selector-switch, an electromagnet for stepping up said switch, means for alternately transmitting different impulses over the line, means for sending impulses of one-character to said magnet to step up the switch, electromagnetically operated means for controlling the operation of the impulse-sending means, and a. key for controlling the operation of ;said electro-magnetically operated controlling means.

65. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a selector-switch, an electro-inagnet for stepping up said switch, means for synchronously sending impulses to said. magnet to step up the switch and over the line, and means for initially sending a restoring impulse over the telephone-line. v

(36. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a'circuit and means for sending impulses over the line, a selectorfswitch and continuously operated electi'o-magnetically operated means for making and breaking the circuit for the transmission of impulses over the line.

67. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means for alternately sending different impulses over the line, and electro-magnetically operated means for making and breaking the circuit to cause different impulses to pass alternately over the line.

combination with switching devices at the sub-stations and a line of a circuit and means for sending impulses over the line, and a and breaking the circuit to cause impulses to pass over, the line.

69. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means for sending impulses over the line, a continuously operating vibrator for making and breaking the circuit to cause impulses to pass over the line, and means for controlling"the circuit to cause a predetermined number of impulses to be sent over the line.

70. In a lock-out telephone system, the combination with switching devices at the substations and a line of a circuit and means for alternately sending different impulses over the line, and a continuously operating electro-magnetically operated vibrator for making and=breaking the circuit-to cause different impulses to pass alternately over the line.

71. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit'and means for' alternately sending difierent impulses 68. In a lock-out telephone system, the

continuously operating vibrator for making over ,the line, a continuously operating electric-magnetically operated vibrator for making and breaking the circuit to cause different impulses to pass alternately over -the line, and means for controlling the circuit to cause a predetermined number of impulses to be sent ove-rthe line.

72.-In. a lock-out telephone system, the .combination 'with switching devices at the sub-stations and a line'of a selector-switch, an elect-ro magnet for stepping up said switch, means for synchronously sending impulses to said magnet to step up the switch tinuously operating electro-magnetically op- 'erated means for making and breaking a circuit for the transmission of impulses over the line, and electro-magn'etically-operated controlling means-for the circuit over which the impulses are transmitted.

71, In a lock-out telephone system, the combination. with switching devices at the sub-stations and a line of a circuit and means for alternately sending'difi'erent impulses over the line, electro-magnetically operated jmeans for making and breaking the circuit tov cause different impulses to pass alternately over the line, and electro-magnetrcally operated controlling-means for the,,circuit.

over which the impulses are transmitted.

75. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means for alternately sending difierent impulses over the line, a continuously operating electro-magnetically operated vibrator for making and breaking the. circuit to' cause diHere-ntimpulscs'to pass alternately over the'line, and electro-magnetically operated controlling-means for the circuit over which the impulses are transmitted. I

76. In a lock-out telephone system, "the combination with switchin devices at the sub-stations and a line of a circuit and means for sending impulses over the line and continuously operating electro-magnetically operated means for making and breaking a circuit for the transmission of impulses overv the line, and an electro-magnetically operated selector-switch operated by impulses of one character.

77. In a lock-out telephone system, the

combination. with switching devices at the sub-stations and a line of clrcuit and means for alternately sending difl'erent impulses over the line, electro-magnetically operated means for making and breaking the circuit to cause diflerent impulses to passfalternately over the line, and an electro-magnetically operated selector-switch operated b impulses of one character.

78. In a lock-out telephone.- system, the combination with switching devices at the sub-stations and a line of a circuit and means for sending impulses over the line, a con--,.

tinuously operating vibrator for making and breaking the circuit t6 cause impulses to pass over the line, and an electro-magnetically operated selector-switch operated by impulses'of one character.

79. In a lock-out telephone system, the combination with switching devices atthe sub-stations and aline of a circuit and means for alternately sehdingdiiferent impulses over the line, a continuously operating electro-magnetically operated vibrator for makmg and breaking the circuit to cause diifer ent, impulses to pass alternately over 'the line, and electro-magnetically operated selector-switch operated by impulses of one character.-

80. In a lock-out telephone system,,, the combination with switching devices at the sub-stations and a line of a circuit and means for sending impulses over the line, a selector-;

switch, and means for establishing a ringing ingan electro-magnet, and a switch operated thereby, and a ringing-key connected to ren-.

der the ringing circuit inoperative said means. for establishing the ringing circuit being rendered operative by the selector switch, and located at the exchange.

82. In a lock-out telephone system, the combination with switching devices at the sub-stations and a line of a circuit and means for sending impulses over the line, a selectorswitch, and means for establishing a ringing circuit after the impulses have been transmitted, comprising an electro-magnet and a switch operated thereby, and an electro-magnet for maintaining the ringing circuit operative.

83. In a lock-out telephone system, the

combination with switching devices at the sub-stations and a line of a circuit and means for sending impulses over the line, aselectorswitch, means for establishing a ringing circuitafter the impulses have been transmit-- ted, comprising an electro-magnet and a switch operated thereby, an electro-magnet for maintaining the ringing circuit operative, and a ringing-keyconnected to render the ringing current inoperative. a

84:. In .a lock-out telephone system, the

combination with switchlng devlces'at the sub-station and a line of a circuit and means for sending impulses over the line, a selectorswiteh, means for automatically establishing a ringing-circuit when a predetermined number of impulses have been transmitted, comprising an electro-magnet and a switch operated thereby, and an electromagnetically operated controlling means for the circuit over which im ulses are sent connected to the last mentioned switch an rem; dered inoperative when the ringing circuit is established,

85. In a lock-out"; l'ephone system, the

-. combination with switch ng devices at the sub-stations and a line of acircuit and means for sending impulses .over the line, electromagnetically operated controlling-means for Copies of thispa tent may be obtained for I said circuit, means for selectively sending an im ulse over the 1ine,'means for automatica ly establishing a signaling-circuit when a predetermined number of impulses have been, sent over the. line, and means for restoring said controlling-means when said pinging circuit is rendered operative.

ARTHUR E. CASE.

Witnesses HILnUn C. PETERSEN,

five cent! each, by addrelaing washingtonm. 0.

FRAN W. BEMM.

the Commissioner 0! Patents,

said circuit, means for automatically esta'b magnetically operated,controlling-means for 

